test: add catalog preview endpoint tests (#969)

Add test coverage for the catalog preview API including:
- Filter validation with includedModels/excludedModels patterns
- filterStatus parameter testing (all/included/excluded)
- Error handling for invalid configs and nonexistent paths
- User-provided catalog data support via catalogData parameter

Implement helper utilities for preview API testing

Enhance test fixtures to support parameterized catalog selection,
enabling tests against both default and validated catalog sources.

Author: fege

tests/model_registry/model_catalog/conftest.py

@@ -15,6 +15,7 @@
     DEFAULT_CATALOG_FILE,
     CATALOG_CONTAINER,
     REDHAT_AI_CATALOG_ID,
+    DEFAULT_CATALOGS,
 )
 from tests.model_registry.model_catalog.utils import get_models_from_catalog_api, get_catalog_url_and_headers
 from tests.model_registry.constants import (
@@ -257,9 +258,31 @@ def randomly_picked_model_from_catalog_api_by_source(
 
 
 @pytest.fixture(scope="class")
-def default_model_catalog_yaml_content(admin_client: DynamicClient, model_registry_namespace: str) -> dict[Any, Any]:
+def default_model_catalog_yaml_content(
+    request: pytest.FixtureRequest, admin_client: DynamicClient, model_registry_namespace: str
+) -> dict[Any, Any]:
+    """
+    Fetch and parse catalog YAML from the catalog pod.
+
+    Defaults to DEFAULT_CATALOG_FILE if not parameterized.
+    Use with @pytest.mark.parametrize indirect parameter to specify a different catalog:
+
+    Args:
+        request.param: Optional catalog ID, if not provided, uses DEFAULT_CATALOG_FILE.
+
+    Returns:
+        Parsed YAML content as dictionary
+    """
+    # If parameterized, get the catalog file path from the catalog ID
+    # Otherwise, use DEFAULT_CATALOG_FILE
+    catalog_id = getattr(request, "param", None)
+    if catalog_id:
+        catalog_file_path = DEFAULT_CATALOGS[catalog_id]["properties"]["yamlCatalogPath"]
+    else:
+        catalog_file_path = DEFAULT_CATALOG_FILE
+
     model_catalog_pod = get_model_catalog_pod(client=admin_client, model_registry_namespace=model_registry_namespace)[0]
-    return yaml.safe_load(model_catalog_pod.execute(command=["cat", DEFAULT_CATALOG_FILE], container=CATALOG_CONTAINER))
+    return yaml.safe_load(model_catalog_pod.execute(command=["cat", catalog_file_path], container=CATALOG_CONTAINER))
 
 
 @pytest.fixture(scope="class")

tests/model_registry/model_catalog/constants.py

@@ -36,6 +36,7 @@
 REDHAT_AI_CATALOG_ID: str = "redhat_ai_models"
 DEFAULT_CATALOG_FILE: str = DEFAULT_CATALOGS[REDHAT_AI_CATALOG_ID]["properties"]["yamlCatalogPath"]
 VALIDATED_CATALOG_ID: str = "redhat_ai_validated_models"
+VALIDATED_CATALOG_FILE: str = DEFAULT_CATALOGS[VALIDATED_CATALOG_ID]["properties"]["yamlCatalogPath"]
 
 MODEL_ARTIFACT_TYPE: str = "model-artifact"
 METRICS_ARTIFACT_TYPE: str = "metrics-artifact"